N.B
these 3 tabs have 3 different header because i need to have different icon on the header for each tab( different function,different behaviour)
when i go to page 2 my back button is disappeared,in EVERY tab.I think the problem is that every tab has its own navcontroller.
if i inspect html and i find the back button if i put display block,the back button appears but when i click to it i get this error.